Patent application title: Medical device

Abstract:

The invention provides a medical device with a retention section for
anchoring the medical device in the body of a living being, a drainage
section for draining fluids from the body, e.g. urine, and a tip which
facilitates insertion into the body. During the anchoring of the medical
device, the tip is retracted toward a proximal end of the device,
improving the users control over the position of the tip relative to
other parts of the device and achieving the free flow of fluids through
the device. An indicator may be provided to give a visual, audible, or
tactile indication of at least a first position of the tip relative to
the remaining part of the medical device.

Claims:

1.-14. (canceled)

15. A drainage catheter, comprising:an elongated drainage section defining
a lumen for draining fluid, said drainage lumen having an opening at a
distal end;a retention section having a configuration wider than said
distal end of said drainage lumen and adapted to retain said catheter at
a desired site, said retention section defining a lumen in communication
with said drainage lumen and being located distally of said drainage
section;a tip having a first position located distally of said retention
section, said tip being connected to said retention section when said
retention section is in said wider configuration;a deployment member
fixedly connected to said tip and operable by a user to retract said tip
from said first position to a second position wherein said tip is at
least partially located in at least one of said retention section and
said drainage section, wherein said tip in said second position does not
block said drainage lumen so that fluid may flow through said drainage
lumen; anda lock adapted to lock said tip in at least one of said first
position and said second position;wherein both of said drainage section
and said retention section are braided, and said braided retention
section is a continuation of said braided drainage section.

16. The drainage catheter according to claim 15, further comprising an
indicator which is adapted to indicate a position of said tip relative to
at least one of said drainage section and said retention section.

17. The drainage catheter according to claim 16 wherein said indicator is
adapted to indicate that said tip is a distal-most end of said catheter.

18. The drainage catheter according to claim 16, wherein said indicator is
adapted to indicate that said tip is received within said retention
section.

19. The drainage catheter according to claim 15 wherein said deployment
member is connected to said retention section and is operable to change
said retention section between a narrow configuration suitable for
insertion of said catheter and said wider configuration.

20. The drainage catheter according to claim 19 wherein said tip is
locatable in said first position when said retention section is in said
narrow configuration, and said tip is locatable in said second position
when said retention section is in said wider configuration

21. The drainage catheter of claim 16 wherein said indicator includes a
tactile indicator.

22. The drainage catheter of claim 16 wherein said indicator includes a
visual indicator.

23. The drainage catheter of claim 22 wherein said visual indicator
includes an indicator provided on a proximal end of said deployment
member.

24. The drainage catheter of claim 23 wherein said visual indicator on
said proximal end of said deployment member includes a particular color.

25. The drainage catheter of claim 22 wherein a proximal portion of said
catheter is transparent so that said visual indicator is observable
through said transparent proximal portion.

26. The drainage catheter according to claim 15 wherein said lock is
adapted to lock said deployment member so that said retention section
remains in one of a narrow configuration suitable for insertion of said
catheter into a patient and said wider configuration, and so that said
tip correspondingly remains in one of said first position and said second
position.

27. The drainage catheter of claim 15 including a connector for connecting
said catheter to a device for collecting fluids drained through said
catheter.

28. The drainage catheter of claim 16 wherein said indicator is adapted to
indicate at least one of said first position and said second position.

29. The drainage catheter according to claim 15 wherein said braided
drainage section includes filaments defining openings therebetween, and
further including a polymer that blocks said openings.

30. A method of using a drainage catheter, comprising:providing a drainage
catheter having an elongated drainage section defining a lumen for
draining fluid, the drainage lumen having an opening at a distal end, a
retention section having a narrow configuration suitable for insertion
into a patient and a wider configuration for retaining the catheter at a
desired site, the retention section in the wider configuration defining a
lumen in communication with the drainage lumen and being located distally
of the drainage section, and a tip having a first position located
distally of the retention section when the retention section is in the
narrow configuration, the tip being moveable into a second position when
the retention section is in the wider configuration wherein the tip is at
least partially located within at least one of the retention section and
the drainage section but does not block the drainage lumen so that fluid
may flow through the drainage section lumen when the tip is in the second
position, wherein both of the drainage section and the retention section
are braided and the braided retention section is a continuation of the
braided drainage section, and a lock adapted to lock said tip in at least
one of said first position and said second position;inserting the
catheter into a patient with the tip in the first position and the
retention section in the narrow configuration;changing the retention
section to the wider configuration;retracting the tip from the first
position to the second position; andlocking the tip in the second
position.

[0002]The present invention relates to a medical device for draining
fluids from the body of a living being. In particular, the invention
relates to a medical device with a distal end for insertion into a body
of a living being and an axially opposite proximal end, the device
comprising: a tip which in a first position forms the distal end of the
device, a drainage section forming a conduit extending in an axial
direction of the device, and a retention section extending between the
draining section and the tip, wherein the tip is operable between the
first position and a second position so as to move the retention section
between a first configuration and a second configuration, in which second
configuration the retention section is expanded in a direction transverse
to the axial direction. More specifically the present invention relates
to a medical device comprising indicating means which indicates when the
tip is in a predetermined posit ion when operated between the first and
second position.

BACKGROUND OF THE INVENTION

[0003]Many people suffer from a variety of medical problems that require
the insertion of a medical device such as a catheter, to drain fluids
from the body. For example, the most common treatment for problems with
the urinary system, such as inability or difficulty in passing urine or
severe incontinence, is to fit a catheter to drain urine from the
bladder. A very well known catheter for this purpose is known as a Foley
catheter. This is a flexible tube, usually made from latex or silicone,
which has a central drainage lumen for the passage of urine and an
inflation lumen communicating with an inflatable balloon incorporated
into its distal end. With the balloon deflated, the catheter tube can be
passed through the urethra into the bladder. Once the balloon is located
in the bladder, it is inflated via the inflation lumen so that the
balloon sits at the neck of the bladder and retains the tube in position.
A tubular extension extends beyond the balloon into the bladder and has
at least one eyelet in its wall through which urine may pass from the
bladder into the central lumen. The urine flows down the tube to its
proximal end situated outside the body which has a connector to which a
collection bag is releasably fitted. The proximal end of the tube also
has an inflation port for connection of a device to inflate the balloon
via the inflation lumen.

[0004]Another type of conventional medical device comprises a tube having
a retention section located at its distal end. The retention section has
a cross-sectional diameter normally greater than the cross-sectional
diameter of the remainder of the tube and of the urethra or other bodily
conduit through which the medical device is to be inserted. To insert or
remove a device of this type, an axial stretching force is applied to the
distal end of the device using an insertion tool such as a rod or boogie
temporarily inserted through the lumen of the device to engage with the
retention section. This elongates or necks down the retention section so
that its cross-sectional diameter reduces or stretches to a diameter
similar to the remainder of the tube and less than that of the bodily
conduit.

[0005]One such medical device is known from U.S. Pat. No. 5,041,093 which
discloses a catheter comprising an axially and radially elastically
extensible, foramenous woven tube having two ends disposed between the
end of a tubular member and a tip, the tip being spaced from the tubular
member. The woven tube is translatable between three configurations;
relaxed, extended and over-center. In the over-center configuration the
woven tube is doubled back on itself to form a cup- or disc-like shape.
The woven tube may be arranged into a tulip-like shape which protectively
encloses the tip. However in this configuration the opening of the
tubular member is more or less blocked by the tip and thus it is desired
to provide a solution wherein the tip is shielded by the over-center
woven tube without blocking the opening of the tubular member.

[0007]It is an object of a preferred embodiment of the present invention
to provide a medical device facilitating better control over the
anchoring mechanism.

DESCRIPTION OF THE INVENTION

[0008]Accordingly, the present invention relates to a medical device with
a distal end for insertion into a body of a living being and an axially
opposite proximal end, the device comprising: a tip which in a first
position forms the distal end of the device, a drainage section forming a
conduit extending in an axial direction of the device, and a retention
section extending between the draining section and the tip, wherein the
tip is operable between the first position and a second position so as to
move the retention section between a first configuration and a second
configuration, in which second configuration the retention section is
expanded in a direction transverse to the axial direction.

[0009]It one embodiment the medical device comprises indicating means
which indicates when the tip is in a predetermined position when operated
between the first and second position.

[0010]An advantage of the present invention is that it is possible for the
user to remote control the position of the tip e.g. such that the tip has
been retracted exactly enough to make sure that it can not irritate the
inner wall of a body lumen e.g. a bladder as a retention section will
partly or completely shield the tip.

[0011]In some of the passages in the remaining part of the description,
the medical device is described with reference to catheters to be
inserted into a urinary drainage, i.e. wherein the catheter is inserted
into a natural or artificial urinary canal e.g. urethra, and into a
bladder for draining urine during use, the catheter could be inserted
into a body opening and guided into a cavity to be drained for body
fluid. The medical device could, however, be used for draining body
fluids in general, be that either subcutaneously or through insertion of
the medical device into a natural or artificial opening in the body, or
the medical device could be applied for stent delivery, e.g. for placing
a stent within the prostatic urethra, or in general for draining fluids
from a natural or artificial body lumen, for anal insertion or for
insertion into the gastric region. Another type of use could be for
intubations or endoscopy.

[0012]The indicating means may be provided as a visible, audible or
tactile signal. The visible signal may be a coloured area or a symbol
provided in the proximal end at a position which extends out of the body
when the medical device is inserted into the body. Furthermore the
visible signal could be a lines or scales provided on a deployment
member. An audible or tactile signal could be generated by two parts
which during relative movement engage or disengage each other and thereby
generates sound or tactile indication. The indicating means may be
provided in the proximal end or at any other part of the device.

[0013]By providing indication means which indicates the position of the
tip of the medical device in relation to the retention section it is
possible for the user to insert the medical device into the body with the
tip in the first position, and to anchor the medical device in the body
by retracting the tip to the second position. During the movement of the
tip between the positions, the user obtains a signal indicating the
position of the tip and thereby obtains improved control over the use of
the medical device. The indicating means may further be adapted to signal
when the tip passes second, third or further positions during the
movement, e.g. one position when the tip is retracted not to form the
distal end, one position wherein the tip is in the area of the conduit
but still not retracted into the conduit, and one position wherein the
tip is located in the conduit and thereby possibly blocks fluid passage.

[0014]The indicating means could form part of a deployment member or form
part of a deployment mechanism provided in the proximal end of the
medical device for controlling the deployment member. As an example, the
deployment member could be constituted by an axially incompressible rod
fastened between the tip of the device and the proximal end of the
medical device, and the axial displacement of the deployment member could
be controlled via a deployment mechanism comprising means allowing axial
elongation or compression of the proximal part of the medical device. For
this purpose, the medical device could have a corrugated proximal end
portion forming bellows and including visually detectable means
indicating the position of the tip in relation the first and optionally
other positions.

[0015]In order to allow the user to lock the medical device in the first
and optionally further positions of the tip, the deployment member or the
deployment mechanism could comprise locking means for locking further
movement of the tip. The locking means may be reversible i.e., adapted to
be locked and un-locked.

[0016]In order to further increase the degree of expansion or to form a
specific shape of the braided portion in the second configuration, a
first part of the braided portion may be located inside a second part of
the braided portion when the device is in the second configuration. The
first and second parts of the braided portion does not have to be
structurally separated, but could form one uniform braided portion, and
merely the fold arising by the inverting or rolling of one part of the
braided portion into another part of the braided portion defines the
transition between the first and second parts of the braided portion. In
the first configuration, the braided portion could extend un-folded in
the axial direction.

[0017]The medical device, especially the retention section, may be
designed with "shape-memory" such that it will automatically move towards
a predetermined shape i.e. towards a relaxed state. In a first embodiment
the medical device is designed such that the predetermined shape is the
first configuration, i.e. the medical device will have a tendency to move
towards the first configuration, but may be moved into the second
configuration by axial displacement of the first part of the braided
portion into a second part of the braided portion. In some embodiments
the first configuration is a configuration wherein the largest dimension
of a cross-section of the retention section is equal or less than the
largest dimension of a cross-section of the drainage section.

[0018]In a second embodiment the medical device is designed such that the
predetermined shape is the second configuration, i.e. the medical device
will have a tendency to move towards the second configuration, but may be
moved into the first configuration by axial displacement of the first
part of the braided portion out of the second part of the braided
portion. In some embodiments the second configuration is a configuration
wherein the largest dimension of a cross-section of the retention section
is larger than the largest dimension of a cross-section of the drainage
section.

[0019]In a third embodiment the medical device is designed such that the
predetermined shape when the retention section is located inside the
remaining part of the medical device, e.g. the drainage section,
coaxially therewith. When the medical device is located in the body, the
second part is displaced out of the remaining part of the medical device
to form a medical device in the second configuration, i.e. retained in
the body. To operate the medical device between the different
configurations, a deployment member could be fastened in the distal end,
e.g. to a distal tip of the medical device, and extend to the proximal
end to facilitate manipulation of the distal end from outside the body.
To facilitate comfortable insertion or to reduce adherence of body tissue
to the surface of the medical device, at least a part of the medical
device, e.g. the braided portion or the second part of the braided
portion or the tip-part may have an outer surface, i.e. a surface towards
the body tissue when the medical device is inserted into the body, which
surface has a low surface friction characteristic compared to other parts
of the medical device. To provide the low friction characteristic, the
braided portion or at least the second part thereof may have a
hydrophilic surface, e.g. provided by a hydrophilic coating of the
surface. A hydrophilic coating may further reduce irritation of the body
tissue, e.g. mucosa. If a hydrophilic coating is applied to the braided
portion, the coating may incorporate an anti-infective compound or a
compound which counteracts ingrowth.

[0020]The retention section may comprise a braided portion with crossed
filaments which mutually form a braiding angle. The braiding angle may
vary along the length of the retention section e.g. such that the
braiding angle in the middle of the retention section is different from
the braiding angle in the top and bottom of the retention section.

[0021]The wording "braided portion" includes in general a device portion
provided with through-going windows, i.e. openings formed from an outer
peripheral surface to an inner peripheral surface and often being
symmetrically arranged to form a uniform grid of windows. More
specifically, the braided portion may comprise cross-braided filaments,
i.e. threads which are braided over and under each other. Preferably, the
braiding enables the filaments to slide relative to each other.
Alternatively, the filaments are arranged in two separate and parallel
layers wherein the filaments of one of the layers extend in a direction
different from the direction of the filaments of the other layer. In each
intersection between a filament of one of the layers and a filament of
another layer, the filaments of the two layers may be joined by adhesion.
The braided portion could also be constituted by a section of the device
with openings forming a mesh-pattern. Irrespective of the type of
braiding, the angle, α, which the filaments form with the axial
direction, is important for determining the degree of radial expansion
and the more precise shape of the retention section which arises when the
first part is displaced into the second part of the braided portion. This
is described in further details later.

[0022]The braiding may be provided in the retention section and/or the
drainage section and/or the deployment member. Furthermore the tip of the
device may be made of the same braided material as the retention section.
In order to provide a homogeneous surface of the tip, the braided
material may be shaped by means of a heated tool or a tool for
plastically deforming the material in to e.g. a bullet-like shape.

[0023]By providing a drainage section comprising a braided material, the
strength of the drainage section is reinforced as the braided section and
an appropriate matrix material constitutes a composite. Accordingly it is
possible to make the wall of the drainage section thinner. Thus for a
given outer diameter of the medical device the cross-sectional flow area
may be larger.

[0024]In the table below, it is indicated how the use of a braided
drainage section can increase the cross section of the conduit in a
catheter.

[0025]Moreover the filaments of the drainage section may form an extension
of the filaments of the retention section.

[0026]At least the drainage section may be at least partially coated with
polymeric material. Furthermore the retention section may be at least
partially coated with polymeric material, the coating on the retention
section being thinner or having the same thickness as the coating on the
drainage section.

[0027]The filaments could e.g. be made from polyester, polyamide,
polyalkane, polyurethane, PET, PBT, Nylon, PEEK, PE, Glass Fibre, Metal
Wire or Acrylic materials or any composition of the mentioned materials.
A preferred material would be PET or polyester.

[0028]The medical device may include a matrix material, e.g. any medical
grade polymer that can be dissolved in a solvent or manufactured as a
polymer emulsion. Examples of these are polyurethane, polyurethane
dispersions, acrylic, PVC, block copolymers (SIS SBS) etc, natural
rubber, silicone, neoprene, nitrile or compositions thereof.
Polyurethane, acrylic, PVC, block copolymers (SIS SBS) etc, natural
rubber, silicone, or EPO or compositions thereof, could be used if the
medical device is made by extrusion or injection moulding.

[0029]In a second aspect the present invention relates to the use of a
braided material for increasing the cross-section of a conduit throughout
a medical device. By providing a braided material in a drainage section
defining a conduit, it is possible to provide a drainage section which is
has a larger cross-section for a given outer diameter. The filaments of
the braiding in the wall of the braided section reinforces said wall and
thus it may be thinner in order to provide the same strength.

DETAILED DESCRIPTION OF THE INVENTION

[0030]Embodiments of the invention will now be described, by way of
example only, with reference to the accompanying drawings, in which:

[0031]FIG. 1 illustrates a longitudinal cross-sectional view of the
medical device with the retention section in a first configuration and
ready for insertion into, or removal from, the patient;

[0032]FIG. 2 illustrates an enlarged view of the distal end portion of the
medical device shown in FIG. 1;

[0033]FIG. 3 illustrates the medical device shown in FIGS. 1 and 2 in a
second configuration in which the retention section has been deployed to
retain the medical device in position in the patient;

[0034]FIG. 4 illustrates a longitudinal cross-sectional view of a second
embodiment in which the retention section is in a first extended
configuration and is ready for insertion into, or removal from the
patient;

[0035]FIG. 5 illustrates an enlarged view of the distal end portion of the
medical device shown in FIG. 4;

[0036]FIG. 6 illustrates the medical device shown in FIGS. 4 and 5 in a
second configuration in which the retention section has been deployed to
retain the medical device in position in the patient;

[0037]FIG. 7 illustrates an enlarged view of the distal end of the medical
device shown in the first embodiment of FIG. 3 or the second embodiment
of FIG. 6;

[0038]FIG. 8 illustrates a longitudinal cross-sectional view of the distal
end of a third embodiment in which the retention section is in a first
configuration and is ready for insertion into, or removal from, the
patient;

[0039]FIG. 9 illustrates a longitudinal cross-sectional view of the distal
end of a fourth embodiment in which the retention section is in a first
configuration and is ready for insertion into, or removal from, the
patient;

[0040]FIG. 10 illustrates the distal end of the medical device of the
third or fourth embodiment in which the retention section has been
deployed into a second configuration to retain the medical device in
position in the patient.

[0041]FIGS. 11-16 show the process of inverting or rolling over a braided
retention section.

[0042]Referring now to the drawings, there is shown in FIG. 1 a medical
device 1, e.g. a catheter, according to an embodiment of the invention in
a first configuration in which it is ready for insertion into a patient,
or removal therefrom. If the medical device is a urinary catheter it may
be urethral such that it may be inserted through the urethra into the
bladder of the patient or suprapubic in which case it is passed
surgically into the bladder through a surgical incision in the abdominal
muscle wall. Alternatively the medical device may be for intubation and
thus be inserted through the esophagus. In other embodiments the medical
device is for anal insertion.

[0043]The medical device 1 comprises an elongate flexible tubular
resilient drainage section 2 having a proximal end 2a connected to a
deployment mechanism 3 and a distal end 2b connected to one end 4a of a
flexible tubular resilient retention section 4. The drainage section 2
has a lumen 6 for the passage of bodily fluids therethrough and is of a
length to enable it to extend from the cavity or bladder to be drained
out of the patient so that its proximal end 2a can be connected to a
collection bag or other receptacle via the deployment mechanism 3. The
other end 4b of the retention section 4 is connected to one end of a
flexible resilient deployment member or rod 5 which is slideable axially
in the direction indicated by arrow "A" (see FIG. 2) within the lumen 6
of the drainage section in response to operation of the deployment
mechanism 3 to which the other end of the deployment member 5 is
attached.

[0044]It should be noted that, throughout the specification, reference to
the distal end refers to the end of the medical device or part of the
medical device which is inserted deeper into the body of the patient and
reference to the proximal end refers to the end of the medical device or
part of the medical device which is closer to the end of the medical
device which remains outside the body of the patient.

[0045]As can be seen more clearly from FIG. 2, which illustrates an
enlarged partial view of the distal end of the medical device 1, the
retention section 4 is held in a generally cylindrical shape and is
almost entirely withdrawn into the lumen of the drainage section, in its
first configuration. The end 4a of the retention section emerges from the
lumen of the drainage section and is rolled over, inverted, invaginated
or doubled back over itself, to connect the very tip 7 of the end 4a of
the retention section to the distal end 2b of the drainage section for
reasons that will become apparent. The opposite end 4b of the retention
section 4 converges and is attached to the end of the rod 5 lying within
the lumen 6 of the drainage section 2.

[0046]The retention section 4 is made from braided material formed from
structural filaments that are cross-braided over and under each other.
The braiding of the filaments is sufficiently spaced so that fluid may
pass through spaces between the filaments and into the lumen 6 when the
retention section 4 is in the second configuration. The braiding is also
spaced enough to enable the interwoven strands or filaments to slide
relative to each other so that the shape of the retention section 4
changes as it moves between the first and second configurations when
forces are applied to it, as will be explained in more detail below.

[0047]The deployment mechanism 3 comprises a tubular component 8 attached
to the proximal end 2a of the drainage section 2 so that the lumen 6 is
coaxial with the tube 8. A portion 9 of the wall of the tube 8 is
corrugated or is in the form of bellows that enable the tubular component
8 to be axially compressed to reduce its length from the extended
non-compressed state shown in FIG. 1 to the compressed state shown in
FIG. 3 and then returned to its original state shown in FIG. 1. The rod 5
passes through the corrugated portion 9 and is connected to the tube 8 so
that as the corrugated portion 9 is compressed and extended, the rod 5
moves axially within the lumen 6 of the drainage section in the direction
indicated by arrows "A" and "B" (see FIG. 2) respectively. The other end
16 of the tube 8 remote from the drainage section 2 widens into a larger
diameter and may be provided with means thereon (not shown) for
connection to a collection bag via a tube.

[0048]FIG. 3 shows the medical device 1 of FIGS. 1 and 2 when the
retention section 4 has been moved into its second configuration after
the device has been positioned within the patient's body and the
retention section has been deployed to retain or anchor the catheter 1 in
position by operating the deployment mechanism 3 to cause the rod 5 to
move axially in the direction of arrow "A". As can be seen most clearly
from the enlarged partial view of the distal end of the catheter 1 in
FIG. 7, the retention section 4 is pushed out of the distal end 2b of the
drainage section 2 and forms the double-walled funnel shaped
configuration due to the nature of the braided material from which the
retention section is formed. The funnel shape of the retention section 4
in the second configuration prevents withdrawal of the medical device 1
from the patient.

[0049]To remove the medical device 1 from the patient, the retention
section is retracted or withdrawn into the distal end of the drainage
section by applying an axial force to the corrugated portion of the
deployment mechanism so that the rod 5 now moves in the opposite
direction as indicated by arrow "B". Once the retention section 4 has
been retracted or withdrawn, the medical device 1 can be removed from the
patient.

[0050]The rolled end 4a of the retention section 4, described in more
detail above, significantly assists the ease by which the retention
section 4 is deployed from the distal end 2b of the drainage section 2.
When the deployment member 5 moves in the direction of arrow "A", the
retention section 4 does not expand or bulge radially against the wall of
the lumen of the drainage section 2 in the direction indicated by arrow
"X" (see FIG. 2). Furthermore, the retention section 4 does not fold up
inside itself within the part of the retention section 5 pressed against
the wall of the lumen 6 before the rod 5 emerges from the distal end 2b
of the drainage section 2, pulling the retention section 4 out of the
distal end 2b of the drainage section 2 with it. On the contrary, the
cross-sectional diameter of the retention section 4 remains substantially
constant whilst it remains within the distal end 2b of the drainage
section 2 and only expands in cross-sectional diameter as it emerges from
the distal end 2b of the drainage section 2 to form the funnel or cup
like shape illustrated in FIG. 3. Furthermore, the retention section 4
does not collapse or fold in on itself as the axial force is exerted
against it by the rod 5. This is due to the rolled end 4a of the
retention section in its first configuration which causes the retention
section to continue to roll round the inverted end so as to become
further inverted or doubled over to a greater extent because the force
required to cause the retention section to bulge radially against the
inner wall of the lumen is greater than the force required for the
retention section to continue rolling round the inverted end 4a.
Therefore, the retention section 4 remains generally tubular in shape
within the distal end of the drainage section 2b and tracks or feeds
round the rolled edge of the inverted end 4a to form the second
configuration illustrated in FIG. 3 in which the retention section is
substantially rolled in half, i.e. half the retention section 4 overlies
the other half of the retention section 4.

[0051]It will be appreciated that the rolled end 4a of the retention
section 4 in the first configuration is advantageous to assist in
deployment of the retention section 4. However, the rolled end is not
essential in this embodiment of the invention. In another unillustrated
embodiment, the retention section may not be inverted at its end 4a in
the first configuration. In this arrangement, the retention section 4 can
still be deployed from the end of the drainage section into the second
configuration illustrated in FIG. 3, but the retention section will first
bulge radially and press against the inner wall of the lumen and then the
retention section will pass up through itself as the rod 5 moves in the
direction of arrow "A". It will be appreciated that, in this embodiment,
the end 4a of the retention section need not emerge from the distal end
of the drainage section 2 and can be fully withdrawn into the drainage
section in the first configuration.

[0052]A second embodiment will now be described with reference to FIGS. 4
to 6. FIG. 4 shows a medical device 10 similar to medical device 1 of
FIG. 1 in which the retention section 11 is generally cylindrical in
shape in the first configuration. However, instead of being withdrawn or
retracted into the lumen 12 of the drainage section 13, the retention
section 11 extends coaxially beyond the end of it and the deployment
member 14 extends through the retention section 11 for connection to its
second end 11b. As the cross-sectional diameter of the retention section
11 is generally less than or the same as the cross-sectional diameter of
the drainage section 13, the medical device 10 can be inserted into or
removed from the patient when it is in this first configuration.

[0053]In this embodiment, the second end 11b of the retention section 11
is rolled over, inverted or doubled back inside itself, to connect the
very tip 15 of the end 11b of the retention section 11 to the end of the
deployment member 14 e.g. a rod, as most clearly shown in FIG. 5 and for
reasons that will become apparent. The opposite end 11a of the retention
section 11 is attached to the distal end 13b of the drainage section 13.

[0054]FIG. 6 shows the medical device 10 of FIGS. 4 and 5 when the
retention section 4 has been moved into its second configuration after
the medical device has been positioned within the patient's body and the
retention section has been deployed to retain the medical device 10 in
position by operating the deployment mechanism 3 to cause the deployment
member 14 to move axially in the direction of arrow "B". As can be seen
most clearly from the enlarged partial view of the distal end of the
medical device 1,10 in FIG. 7, the end 11b of the retention section 11 is
pulled by the rod 14 so that more of it is inverted or folded into itself
to form the double-walled funnel shaped configuration, due to the nature
of the braided material from which the retention section is formed. The
funnel shape of the retention section 11 in the second configuration
prevents withdrawal of the medical device 10 from the patient.

[0055]To remove the medical device 10 from the patient, the rod 5 is
pushed in the direction of arrow "A" so that the retention section 4
returns to the position shown in FIG. 5.

[0056]The rolled end 11b of the retention section 11, described in more
detail above, assists the ease by which the retention section 11 moves
from the first to the second configuration when the end 11b of the
retention section 11 is pulled by applying an axial force to the
deployment member 14 in the direction of the arrow "B". Instead of
bulging or expanding radially outwardly in the direction indicated by
arrow "X" before a continued application of the pulling force on the
retention section 11 causes the end 11b to flip inside out or over-centre
to form the double walled funnel-like shape, the rolled end 11b causes
the retention section 11 to continue to roll, track or feed round the
inverted end 11b so as to become further inverted or doubled over to a
greater extent with limited or no initial bulging in a radial direction.
Therefore, the funnel is formed gradually and in a controlled manner as
the rod 5 is pulled. As the force required to cause the retention section
to bulge is greater than the force required for the retention section to
continue rolling round the inverted end 4b, the retention section 11
remains generally tubular in shape and tracks round the rolled edge of
the inverted end 11b to form the second configuration illustrated in FIG.
3 in which the retention section is substantially rolled in half, i.e.
half the retention section 11 overlies the other half of the retention
section 11.

[0057]It will be appreciated that the first and second embodiments can be
combined into one medical device in which the second configuration is an
intermediate position between two optional first configurations in which
the rod 5,14 is pulled to withdraw the retention section 4,11 into the
lumen 6,12 of the drainage section 2,13, as described with reference to
the first embodiment or, the rod 5,14 is pushed to cause the retention
section 4,11 to elongate or extend beyond the distal end 2b,11b of the
drainage section 2,13, as described with reference to the second
embodiment.

[0058]It will be apparent that the deployment member 5,14 remains within
the lumen 6,12 of the drainage section 2,13 and is not removed therefrom
once the medical device 1,10 is in position. The deployment member 5,14
may therefore be integrally formed with the retention section 4,11 or may
be made separately and permanently connected thereto by, for example,
welding. To ensure free passage of fluid through the lumen 6,12 of the
drainage section 2,13 the diameter of the rod 5,14 is much smaller than
the diameter of the lumen 6,12 so that fluid can pass freely down through
the lumen 6,12 around the rod 5,14. As the rod 5,14 remains in the lumen
6,12, insertion and removal of the medical device 1,10 is simplified.

[0059]Another embodiment is illustrated in FIG. 8 which is identical to
the embodiment of FIG. 1 except that the deployment member 5 is a tube 20
which has a cross sectional outer diameter only slightly less than the
cross sectional diameter of the lumen 6 of the drainage section 2 so that
it can slide in an axial direction within the lumen 6. In this case,
bodily fluids pass down through a lumen 21 in the tube 20 rather than
through the lumen 6 of the drainage section 2.

[0060]The embodiment of FIG. 9 is identical to the embodiment of FIG. 4
except that the deployment member 14 is a tube 20, as explained with
reference to the embodiment of FIG. 8.

[0061]FIG. 10 shows the medical device 1,10 of FIGS. 8 and 9 when the
retention section 4,11 has been deployed into the second configuration.

[0062]Again, it will be appreciated that the embodiments of FIGS. 8 and 9
can be combined to form a medical device in which the second
configuration illustrated in FIG. 10 is an intermediate position between
optional first configurations illustrated in FIGS. 8 and 9 respectively.

[0063]The drainage section 2,13, the retention section 4,11 and the
deployment member 5,14 of the medical device 1,10 of any of the
embodiments of the invention may be manufactured as a single integral
entity or continuum of material. Each section can be formed from braided
material and changes in braid angle can be used, for example, between the
drainage section 2,13 and the retention section 4,11 to control the
degree by which these sections may vary in their cross-sectional diameter
as an axial force is applied by the deployment member 5,14.

[0064]The deployment member 5,14 may be manufactured separately and
permanently connected to the retention section 4,11 and/or the deployment
mechanism 3 or it may be integrally formed with the retention section
4,11 and/or the deployment mechanism 3. For example, the monofilament
braids of the retention section may be grouped or reduced in number to
form the deployment member 5,14 and so be formed from a continuum of the
retention section 4,11.

[0065]The deployment mechanism 3 may be integrally formed with the
drainage section 2,13 or be fabricated as a separate component which is
later removably or permanently joined thereto. The corrugated portion 9
may also be partially or wholly fabricated separately from the remainder
of the tube 8 by, for example, injection or blow moulding. For example,
the corrugated portion 9 may be formed separately to or integral with the
end part 16 of the tube 8. Alternatively, the corrugated portion may be
formed separately to the part of the tube 8 that connects it to the
drainage section.

[0066]A locking device may be incorporated with the deployment mechanism 3
to maintain the corrugated portion 9 in either position and so prevent
relative movement of the deployment member 5,14 with respect to the
drainage section 2,13 until it is released. The relaxed state of the
corrugated section is preferably as shown in FIGS. 3 and 4 and so it may
not be necessary to provide a locking mechanism to hold the corrugated
portion in the collapsed states shown in these figures. However, it is
desirable to provide a locking mechanism to prevent the corrugated
portion 9 from collapsing back into the configuration shown in FIGS. 3
and 4 when it has been axially stretched into the configuration shown on
FIGS. 1 and 6 and subsequently released. It should be understood that the
locking mechanism should be reversible i.e. the locking mechanism be able
to lock and un-lock.

[0067]It will be appreciated that the medical device 1,10 is not limited
for use with the deployment mechanism 3 described and that other types of
deployment mechanism may be used to move the deployment member 5,14
relative to the drainage section 2,13.

[0068]The medical device 1,10 of the invention is made from a
bio-compatible polymer material which may be polyurethane coated.
However, in a preferred embodiment, the retention section 4,11 is not
coated so that the braids remain open and relative movement between the
braids is enabled. It is also envisaged that there could be a thinner
coating on the retention section 4,11 but which is not so thick so as to
prevent relative movement between the braids relative to each other. The
retention section 4,11 and the drainage section 2,13 could both be coated
during the manufacturing process and areas of the coating can
subsequently be removed by, for example, ablation to improve the
compliancy of those areas. The braiding of the drainage section may or
may not be coated and/or instead the braiding may be welded at
overlapping points to modify the degree of compliancy. Similarly, some of
the overlapping points in the braiding of the retention section may be
welded to modify the degree of compliancy of the retention section.

[0069]The retention section 4,11 may be formed from a non-braided material
which acts in the same way as the braided material and will expand as it
moves into the second configuration. However, a braided material is
preferred and the filaments can be made from a number of different
materials such as metallic wires, polypropylene, nylon, polyurethane or
polyethylene.

[0070]The drainage section 2,13 may also be made from the same braided
material as the retention section 4,11 including structural filaments
that are arranged at an angle such that the cross-sectional diameter of
the drainage section 2,13 decreases when an axial force is applied to the
retention section 4,11 via the deployment member 5,14 but returns to its
original diameter when the force is removed. However, the drainage
section 2,13 can be made from braided material which is coated so that
movement of the filaments relative to each other is restricted. The use
of a braided structure increases the strength of the medical device 1,10
and its kink resistance. Furthermore, because there is no inflation
lumen, an increase in the diameter of the lumen 6,12 is enabled and
allows higher flow rates through the medical device 1,10.

[0072]Many modifications and variations of the invention falling within
the terms of the following claims will be apparent to those skilled in
the art and the foregoing description should be regarded as a description
of the preferred embodiments only.

[0073]In the following the FIGS. 11-16 are described in detail. The figs.
show the process of inverting, rolling over, invaginating, or doubling
back the retention section of a medical device of an embodiment of the
present invention.

[0074]In FIG. 11 the medical device 100 is in a stretched state wherein it
is possible to insert the medical device into a body of a living being
e.g. into a bladder through the urethra. The medical device 100 comprises
a braided retention section 102 comprising a bottom part 104, a middle
part 106 and a top part 108. As may be seen from the figure the braiding
angle of the filaments is different in the middle part 106 than in the
bottom and top part 104, 108. The braiding has a first angle, α, in
the top part 108, a second angle, β, in the middle part 106 and a
third angle, δ, bottom part 104. In the disclosed embodiment,
α equals δ

[0075]Furthermore the medical device 100 is provided with a tip 110 at the
distal end 112 for facilitating insertion of the medical device. At the
proximal end 114 there is provided a connector 116 adapted to be
connected to e.g. a drainage bag (not shown).

[0076]A slidable coupling 188 with tactile indication of its position is
provided between the connector 116 and a drainage section 120. The
slidable coupling 118 comprises a corrugation 122, provided on an outer
surface of the drainage section, and a first and second recess 124,126.
The corrugation 122 is adapted to engage the first recess 124 and the
second recess 126 and to slide between said two recesses. One advantage
of such a slidable coupling is that it makes it possible to provide a
compact medical device which prior to use is provided in a compacted
state and may be extended into an operable state when the medical device
is to be used. In the compacted state the corrugation 122 engages the
first recess 124 and in the operable state the corrugation engages the
second recess 126. A further advantage is that the user may sense e.g. in
the fingertips when the corrugation is brought into or out of engagement
with one of the recesses. This may be used to signal a predetermined
relative position of the tip to the user. This is useful as the user in
the use situation is not able to see the tip as it is provided inside the
body.

[0077]FIGS. 12 and 13 show two different embodiments of the medical
device. The drainage section 120 in FIG. 12 comprises a braiding whereas
the drainage section 120 in FIG. 13 does not comprise a braiding. The
provision of a braiding reinforces the drainage section such that a
conduit with a larger cross-section may be provided for the same outer
diameter of the device. In FIG. 12 the tip is solid whereas the tip in
FIG. 13 is ring shaped with an open end. The ring shaped tip is shown in
detail in FIG. 14 wherein it may be seen that it a conduit 128 which
makes is possible to provide a flow passage from the bladder into the
drainage section 120 even if the tip 120 closely fits the drainage
section 120. The ring shaped tip is attached to the deployment member
130.

[0078]A deployment member 130 may be used to move the tip 110. The tip is
gradually moved in FIG. 11-16 from a state wherein the braided retention
section 102 is stretched in FIG. 11 in to a position wherein the braided
retention section forms a funnel 132 in FIG. 15. In FIG. 15 the tip is
moved to a position wherein it does not constitute the distal end of the
medical device. On the contrary the distal end in FIG. 15 is the rim
portion 134 of the funnel.

[0079]The connector 116 may be transparent such that the deployment member
130 is visible, and at the same time the deployment member 130 may be
provided with sections of different colour indicating the position of the
tip. Thus when the deployment member has been pulled out to a
predetermined position a signalling colour e.g. red may be visible and
indicate a relative position of the tip in relation to the conduit, the
drainage section or the retention section. In another embodiment the
deployment member comprises a visible scale which indicated the position
of the tip.

[0080]In FIG. 16 may be seen that in some embodiments the connector 116
may be disconnected from the drainage section 120 in order to obtain a
funnel shape of the retention section.